Mileage change with smaller lighter trailer

Our old trailer had 56 sqft frontage, weighed 4000#, new is 64 sqft, 7500# and a foot higher off the ground. 12.5 mpg versus 10.0 on reg gas (10.7 with premium).

That's over 10's of thousands km, so is a good estimate of the difference with the F150 EcoB anyway.

The advantage of lighter trailers is being able to tow with lighter vehicles that have smaller engines. Air drag is important but to get a big change you will need to go with a popup type of trailer.

Bayoubass wrote:
It seems to me that almost anything you are towing with (TV) and what ever you are towing, the average MPG is about 7-11 mpg no matter what,not much difference. I get about 10mpg with an 03 F150 4.6L towing a 21 foot Keystone that weighs 4100lbs. empty.

Correct, and I have towed with a lot of combinations. Some tow vehicles are capable of much better mileage when not towing. That is about the only place to save much fuel.

It seems to me that almost anything you are towing with (TV) and what ever you are towing, the average MPG is about 7-11 mpg no matter what,not much difference. I get about 10mpg with an 03 F150 4.6L towing a 21 foot Keystone that weighs 4100lbs. empty.

Turtle n Peeps wrote:

My real world testing proves otherwise! Like I said I saved around $200 on my round trip to MB from Chicago. and the truck didn`t work as hard. just to test it on that trip I lowered the wing for 1 tank and my mileage dropped back to the 6.8mpg I was getting without it, and you could feel the wind drag much more. The wings work if set up properly. the key is placement and angle. I have it so the air is up and over the trailer before it curls back in front of it.

I have a friend that swears he gets 50% better fuel mileage with HHO he put on his car. Physics proves him wrong but he still swears that it works.

If this worked as good as you say it does almost every TV with a TT on the tail would have one on it. Spoilers and wings are nothing new or mysterious and neither are wind tunnels. If these things worked as well as you say yours does the spoiler market would be exploding and they would show wind tunnel tests of an independent tester. It's not, and they don't.

Just look at a few wind tunnel tests to see why they don't work as good as you say. Or you can go talk to a few people that own V nose trailers (way less head-on air than a conventional trailer and spoiler) and see what they say. Almost all will say they were disappointed with no mileage gain.

On a side note; those that own an Airstream trailer will pick up a bit of mileage over a conventional box TT. This makes sense because they are aerodynamic in both the front and rear of the trailer.

Lastly, Kenworth can only pick up 1 to 2% with their most advanced aero package. Look at the chart at 3:11. You claim what; 15% or so? Maybe they should put the brand spoiler you have on there rigs to pick up another 13% or so? :W

That`s because most people don`t understand physics! if they did they would have these. and even if they did, they may not know how to set them up. as you say Airstreams will get better mileage for the same Aerodynamic reasons. and yes my numbers are accurate, I have no reason to make any of this up. I only paid $75 so I`m not trying to justify a big $$$ purchase to improve mileage. keep in mind my trailer is also 11.5 feet tall. so it is a foot taller than most traditional TT`s. my buddy with a 10.5 foot TT can get near 9 mpg, so the wing does help alleviate the height by pushing the air up and over the trailer.

My real world testing proves otherwise! Like I said I saved around $200 on my round trip to MB from Chicago. and the truck didn`t work as hard. just to test it on that trip I lowered the wing for 1 tank and my mileage dropped back to the 6.8mpg I was getting without it, and you could feel the wind drag much more. The wings work if set up properly. the key is placement and angle. I have it so the air is up and over the trailer before it curls back in front of it.

I have a friend that swears he gets 50% better fuel mileage with HHO he put on his car. Physics proves him wrong but he still swears that it works.

If this worked as good as you say it does almost every TV with a TT on the tail would have one on it. Spoilers and wings are nothing new or mysterious and neither are wind tunnels. If these things worked as well as you say yours does the spoiler market would be exploding and they would show wind tunnel tests of an independent tester. It's not, and they don't.

Just look at a few wind tunnel tests to see why they don't work as good as you say. Or you can go talk to a few people that own V nose trailers (way less head-on air than a conventional trailer and spoiler) and see what they say. Almost all will say they were disappointed with no mileage gain.

On a side note; those that own an Airstream trailer will pick up a bit of mileage over a conventional box TT. This makes sense because they are aerodynamic in both the front and rear of the trailer.

Lastly, Kenworth can only pick up 1 to 2% with their most advanced aero package. Look at the chart at 3:11. You claim what; 15% or so? Maybe they should put the brand spoiler you have on there rigs to pick up another 13% or so? :W

Turtle n Peeps wrote:
OP, yes you will get better mileage. You will go from 7.8 to around 8.0. And that's if you tow in the mountains a lot. :)

No matter what people say, V trailers, spoilers, air tabs, wings and the such are not much use. Wind is very sneaky and very counter intuitive and wants to do it's own thing.

If you did aero tests on a wing on an SUV or truck you would find out that the wind gets pushed over and around the wing and then immediately wants to fill in the void of the vacuum the wing just created.
This depends on where the wing is mounted in relation to the trailer. it needs the proper distance and correct angle.

Also the underside and back of the trailer has just as much or more resistance to air than the front. That's why you see a lot of long haul trucks that have side skirts now. Even then it's very little help. But if they pick up a 10th of a MPG and the company has 500 trucks on the road that can add up pretty quickly for them.
True, but our trailers sit quite a bot lower than a semi trailer.

For the average RVer, not so much. On my vacation this year I traveled 5,700 miles. Even if I saved a miracle of 1 MPG with a wing or whatever I would have only saved about a tank of fuel over the 5,700 miles.
A tank of fuel is pretty substantial. between $100 and $150.

There are a few V nose trailer sites out there on the WWW. If you go to one I'm sure they will all confirm what I told you about the mileage.

My real world testing proves otherwise! Like I said I saved around $200 on my round trip to MB from Chicago. and the truck didn`t work as hard. just to test it on that trip I lowered the wing for 1 tank and my mileage dropped back to the 6.8mpg I was getting without it, and you could feel the wind drag much more. The wings work if set up properly. the key is placement and angle. I have it so the air is up and over the trailer before it curls back in front of it.

OP, yes you will get better mileage. You will go from 7.8 to around 8.0. And that's if you tow in the mountains a lot. :)

No matter what people say, V trailers, spoilers, air tabs, wings and the such are not much use. Wind is very sneaky and very counter intuitive and wants to do it's own thing.

If you did aero tests on a wing on an SUV or truck you would find out that the wind gets pushed over and around the wing and then immediately wants to fill in the void of the vacuum the wing just created.

Also the underside and back of the trailer has just as much or more resistance to air than the front. That's why you see a lot of long haul trucks that have side skirts now. Even then it's very little help. But if they pick up a 10th of a MPG and the company has 500 trucks on the road that can add up pretty quickly for them.

For the average RVer, not so much. On my vacation this year I traveled 5,700 miles. Even if I saved a miracle of 1 MPG with a wing or whatever I would have only saved about a tank of fuel over the 5,700 miles.

There are a few V nose trailer sites out there on the WWW. If you go to one I'm sure they will all confirm what I told you about the mileage.

Has anyone ever tried air tabs or a similar product? I remember as a kid watching drag racing and I saw that Budweiser's funny cars first started using them. I know that some tractor trailer operators use them, but I want to know if anyone on RV.net has used them.

Thanks

I gained any where from 1-2 mpg taking off my TT and pulling my bobcat and trailer that weighed 3000 lbs MORE than the TT. ALL due to aerodynamics, ie less wind resistance! When I pulled my track hoe on the same trailer as the bobcat to eastern was, total gcwr was the same, I got 2 mpg, and was typically a gear taller and 5-7 mph faster on the grades than with my TT. AGAIN, due to aerodynamics!

A deflector should help some, big rigs are using deflectors a lot. How much you get in mpg, and is it worth the coin, how long is the ROI? can all make up whether it is worth it or not needs to be decided. Any trailer with smooth(er) sides than you have now, more angled front, lower to the ground etc, even if the same weight, will/should net better mpg's. Takes about 105 hp to move 15K at 60 mph with 70sq ft of frontal area, 135hp at 15K/ 90sq ft, same HP as 25K at 70 sq ft! Weight is not always the end all be all of mpgs and amount of fuel to be used.

Marty